A spokesperson for RealAge said the site pulled from an online health assessment and examined the 50 largest metropolitan areas in the U.S. to find out how quickly residents are aging.

“In compiling the rankings, RealAge analyzed test results from a random sample of 1,000 individuals in each city. The test uses a powerful scientific algorithm that combines the latest medical and nutritional studies with lifestyle, genetics and medical history to calculate a person’s real age.”

High rates of sleep, exercise and happy marriages can boost a city’s youth ranking. But high rates of smoking and hypertension does the opposite.